Control of Echinochloa crus-galli in rice with different POST herbicide treatments

Abstract

The field trials were conducted at two localities during 2013 and 2014 to evaluate different POST herbicide programs for effective E. crus-galli control in rice production regions in the Republic of Macedonia. Herbicide selectivity and influence on grain yield were evaluated, as well. Herbicides were applied in 3 POST herbicide programs: early-postemergence (EPOST), mid-postemergence (MPOST) and late-postemergence (LPOST). E. crus-galli control diff ered among POST herbicides, herbicide programs, and DAT. In Kočani locality E. crus-galli control across POST herbicide programs was 95 to 92% at EPOST and MPOST treatments at 14 DAT, and 99 to 98% at 28 DAT, respectively. Significantly lower efficacy was provided in LPOST treatment (87% and 83%) at both estimation periods. E. crus-galli control across POST herbicide programs in Vinica locality was similar as in Kočani locality. 14 DAT efficacy was ranged between 97 and 93% at EPOST and MPOST treatments, and 28 DAT efficacy was ranged between 99 and 97% at same POST treatments, respectively. Significantly lower efficacy was provided in LPOST treatment (82% and 81%, 14 and 28 DAT, respectively). In both localities all EPOST and MPOST applied herbicides resulted in rice yield which was not statistically different from rice yield in the weed-free control. Because each LPOST herbicide provided lower E. crus-galli control, and caused rice injury, there was significant yield reduction in all plots treated with LPOST herbicides.